Hithertore varieties of tooth brushes for cleaning ones' tooth casing have been devised for practical use and users have in reality used these brushes under the instructions of dental surgeons. However, the realities are that how many times they may have correctly practiced under the instructions they are not able to get rid of cavities in teeth which are gradually getting worse, without the slightest symptoms of decayed teeth getting better and better.
One of the main reasons of the above-mentioned decayed tooth geting more serious is, among many others, partly due to the fact that a stress is exclusively put on cleaning operations of the casing of dental portions and gingival portions, with the least significance being put on a finger massage operation to their gingival portions and partly due to the fact that most of the conventional tooth brushes have in the grip portion of the shank thereof formed so as to stop rotation of the intermediate portion thereof by holding the latter between the users' thumb and first finger so that when the grip portion is firmly grasped by the hand, the shank is easily made to rotate, failing to completely clean a row of teeth and gingival portion closely in contct therewith.